The Masai and the "evil trade"

Even the legendary explorer Dr David Livingstone had many challenges and close shaves in dealing with the Masai. Strangely enough it seems that the Masai had a way of analyzing and gauging those wishing to pass through their vast territory. Clearly they were able to tell the difference between people genuinely out to help like Dr Livingstone and those who promoted slave trade and were out to ultimately harm and capture Africa tribesmen for the evil trade.